The moment Scarlett Pomers stepped onto the Reba set Aug. 10, castmates knew something was wrong. Usually a thin 99 lbs., the 5'2" actress had withered to a skeletal 73 lbs. And the once outgoing 16-year-old was "quiet and depressed," says her rep Rhonda Boudreaux. "Everyone on the show has been very concerned about her."

With good cause. Pomers was barely eating, and exercising as much as six hours a day, often in secret. In early September, after filming just two episodes of the WB sitcom, she took a medical leave of absence and about a month ago entered a facility to be treated for anorexia. "It took several weeks just for her to be able to overcome the urge to work off every calorie she ate," says a close family member. "But she realized that in order to get her life back, she must fight this."

The illness started last winter as she tried to shed weight put on over the holidays. The pounds continued to drop after summer plans to shoot a movie and finish her first album fell through. "She felt that everything in her life was out of control," says Boudreaux. Alarmed, her mother sent her to a doctor, a therapist and a nutritionist. By summer's end Pomers had put some weight back on, but when production on Reba was delayed and the show almost canceled, Boudreaux says, "the stress began to wear down the progress she had made."

Pomers's family hopes going public will raise awareness of the disease and the "incredibly destructive Web sites" that encourage eating disorders and taught Pomers how to hide her illness. Now on the mend, "Scarlett wants girls to know there is no shame in being ill and seeking help," says a family member. "Hiding it only makes the disease dig its way deeper into their lives."